package org.apache.maven.configuration.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.File;

import org.apache.maven.configuration.BeanConfigurationException;
import org.apache.maven.configuration.BeanConfigurationPathTranslator;
import org.apache.maven.configuration.BeanConfigurationRequest;
import org.apache.maven.configuration.BeanConfigurationValuePreprocessor;
import org.apache.maven.configuration.BeanConfigurator;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.configurator.ComponentConfigurationException;
import org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter;
import org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup;
import org.codehaus.plexus.component.configurator.converters.lookup.DefaultConverterLookup;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
import org.codehaus.plexus.configuration.PlexusConfiguration;
import org.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
import org.codehaus.plexus.util.xml.Xpp3Dom;

/**
 * <strong>Warning:</strong> This is an internal class that is only public for technical reasons, it
 * is not part of the public API. In particular, this class can be changed or deleted without prior
 * notice.
 * 
 * @author Benjamin Bentmann
 */
@Component(role = BeanConfigurator.class)
public class DefaultBeanConfigurator implements BeanConfigurator {

  private final ConverterLookup converterLookup = new DefaultConverterLookup();

  public void configureBean(BeanConfigurationRequest request) throws BeanConfigurationException {
    if (request == null) {
      throw new IllegalArgumentException("bean configuration request not specified");
    }

    if (request.getBean() == null) {
      throw new IllegalArgumentException("bean to be configured not specified");
    }

    Object configuration = request.getConfiguration();
    if (configuration == null) {
      return;
    }

    PlexusConfiguration plexusConfig = null;
    if (configuration instanceof PlexusConfiguration) {
      plexusConfig = (PlexusConfiguration) configuration;
    } else if (configuration instanceof Xpp3Dom) {
      plexusConfig = new XmlPlexusConfiguration((Xpp3Dom) configuration);
    } else {
      throw new BeanConfigurationException(
          "unsupported bean configuration source (" + configuration.getClass().getName() + ")");
    }

    if (request.getConfigurationElement() != null) {
      plexusConfig = plexusConfig.getChild(request.getConfigurationElement());
    }

    ClassLoader classLoader = request.getClassLoader();
    if (classLoader == null) {
      classLoader = request.getBean().getClass().getClassLoader();
    }

    BeanExpressionEvaluator evaluator = new BeanExpressionEvaluator(request);

    ObjectWithFieldsConverter converter = new ObjectWithFieldsConverter();

    try {
      converter.processConfiguration(converterLookup, request.getBean(), classLoader, plexusConfig, evaluator);
    } catch (ComponentConfigurationException e) {
      throw new BeanConfigurationException(e.getMessage(), e);
    }
  }

  static class BeanExpressionEvaluator implements TypeAwareExpressionEvaluator {

    private final BeanConfigurationValuePreprocessor preprocessor;

    private final BeanConfigurationPathTranslator translator;

    public BeanExpressionEvaluator(BeanConfigurationRequest request) {
      preprocessor = request.getValuePreprocessor();
      translator = request.getPathTranslator();
    }

    public Object evaluate(String expression, Class<?> type) throws ExpressionEvaluationException {
      if (preprocessor != null) {
        try {
          return preprocessor.preprocessValue(expression, type);
        } catch (BeanConfigurationException e) {
          throw new ExpressionEvaluationException(e.getMessage(), e);
        }
      }
      return expression;
    }

    public Object evaluate(String expression) throws ExpressionEvaluationException {
      return evaluate(expression, null);
    }

    public File alignToBaseDirectory(File file) {
      if (translator != null) {
        return translator.translatePath(file);
      }
      return file;
    }

  }

}
